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Assertion: The megasporangia, commonly c...

Assertion: The megasporangia, commonly called ovules arise from placenta.
Reason: The number of ovules in an ovary may be one as in wheat, mango etc., to many an in papaya, watermelon and orchids .

A

Assertion and reason both are correct statements and reason is the correct explanation of the assertion.

B

Assertion and reason both are correct statements, but reason is not the correct explanation of the assertion.

C

Assertion is true, but reason is false statement.

D

Assertion is false, but reason is true statement.

Text Solution

AI Generated Solution

The correct Answer is:
To solve the question, we need to analyze both the assertion and the reason provided. ### Step-by-Step Solution: 1. **Understanding the Assertion**: - The assertion states that "The megasporangia, commonly called ovules, arise from the placenta." - In botanical terms, the megasporangium (or ovule) is indeed attached to the placenta, which is the part of the ovary that supports the ovules. This statement is true. 2. **Understanding the Reason**: - The reason states that "The number of ovules in an ovary may be one as in wheat, mango, etc., to many as in papaya, watermelon, and orchids." - This statement is also true. Different plants can have varying numbers of ovules in their ovaries. For example, wheat and mango typically have one ovule per ovary, while plants like papaya and watermelon can have multiple ovules. 3. **Analyzing the Relationship**: - While both the assertion and the reason are true, we need to determine if the reason correctly explains the assertion. - The assertion talks about the origin of ovules from the placenta, while the reason discusses the variability in the number of ovules among different plants. The reason does not provide a justification for the assertion. 4. **Conclusion**: - Since both statements are true but the reason does not explain the assertion, the correct answer is that both the assertion and reason are correct statements, but the reason is not the correct explanation of the assertion. ### Final Answer: - The assertion is true, the reason is true, but the reason is not a correct explanation of the assertion. Therefore, the answer is option B. ---
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The arrangement of the ovules on the placenta developed from the central axis of the ovary is called

Read the following text and answer the following questions on the basis of the same: Gynoecium, is the female reproductive part of the flower. It may consist of a single or more than one pistil. These pistil may be free or fuse. Each pistils has three parts, stigma, style and ovary. Ovary has an ovarian cavity, which has one or many chambers or locules. The placenta is located inside the ovarian cavity. Megasporangia or ovules arise from the placenta. In which of the following plants the number of ovules in an ovary is one ?

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Read the passage given below and answer the following questions: Within the 3d series, manganese exhibits oxidation states in aqueous solution from +2 to +7, ranging from Mn^(2+)(aq) to MnO_(4)^(-) (aq). Likewise, iron forms both Fe^(2+)(aq) and Fe^(3+)(aq) as well as the FeO_(4)^(2-) ion. Cr and Mn form oxyions CrO_(4)^(2-) , MnO_(4)^(-) , owing to their willingness to form multiple bonds . The pattern with the early transition metals-in the 3d series up to Mn, and for the 4d, 5d metals up to Ru and Os—is that the maximum oxidation state corresponds to the number of ‘‘outer shell’’ electrons. The highest oxidation states of the 3d metals may depend upon complex formation (e.g., the stabilization of Co^(3+) by ammonia) or upon the pH (thus MnO_(4)^(2-) (aq) is prone to disproportionation in acidic solution). Within the 3d series, there is considerable variation in relative stability of oxidation states, sometimes on moving from one metal to a neighbor, thus, for iron, Fe^(3+) is more stable than Fe^(2+) , especially in alkaline conditions, while the reverse is true for cobalt. The ability of transition metals to exhibit a wide range of oxidation states is marked with metals such as vanadium, where the standard potentials can be rather small, making a switch between states relatively easy. (Cotton, S. A. (2011). Lanthanides: Comparison to 3d metals. Encyclopedia of inorganic and Bioinorganic Chemistry.) In the following questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices on the basis of the above passage. Assertion: The highest oxidation states of the 3d metals depends only on electronic configuration of the metal. Reason: The number of electrons in the (n-1)d and ns subshells determine the oxidation states exhibited by the metal.

In which placentation type , the ovary is two to many chambered and the ovules arise from central axis?

Read the passage given below and answer the following questions: Within the 3d series, manganese exhibits oxidation states in aqueous solution from +2 to +7, ranging from Mn^(2+)(aq) to MnO_(4)^(-) (aq). Likewise, iron forms both Fe^(2+)(aq) and Fe^(3+)(aq) as well as the FeO_(4)^(2-) ion. Cr and Mn form oxyions CrO_(4)^(2-) , MnO_(4)^(-) , owing to their willingness to form multiple bonds . The pattern with the early transition metals-in the 3d series up to Mn, and for the 4d, 5d metals up to Ru and Os—is that the maximum oxidation state corresponds to the number of ‘‘outer shell’’ electrons. The highest oxidation states of the 3d metals may depend upon complex formation (e.g., the stabilization of Co^(3+) by ammonia) or upon the pH (thus MnO_(4)^(2-) (aq) is prone to disproportionation in acidic solution). Within the 3d series, there is considerable variation in relative stability of oxidation states, sometimes on moving from one metal to a neighbor, thus, for iron, Fe^(3+) is more stable than Fe^(2+) , especially in alkaline conditions, while the reverse is true for cobalt. The ability of transition metals to exhibit a wide range of oxidation states is marked with metals such as vanadium, where the standard potentials can be rather small, making a switch between states relatively easy. (Cotton, S. A. (2011). Lanthanides: Comparison to 3d metals. Encyclopedia of inorganic and Bioinorganic Chemistry.) In the following questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices on the basis of the above passage. Assertion: Vanadium had the ability to exhibit a wide range of oxidation states. Reason: The standard potentials Vanadium are rather small, making a switch between oxidation states relatively easy.

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